Plants shape soil microbial communities through their root architecture, their rhizodeposits and return of dead plant material to the soil. These interactions can have a strong influence on the soil organic carbon dynamics. However, it is unclear whether the plant species effects on the soil microbial community could influence the organic carbon mineralization through plant legacy effects. Therefore, we examined how and to what extent a short-term plant growing phase affected the total and active soil microorganisms and through a possible plant legacy, also the mineralization of soil organic carbon, a central ecosystem function. Using a controlled pot experiment, we first showed that the two phylogenetically distinct plants, Arabidopsis thaliana and Triticum aestivum, differently shaped the soil microbial communities when recruiting from the same soil community. Although both plants recruited plant-growth promoting bacteria in the vicinity of their roots, A. thaliana had a stronger effect than T. aestivum and also recruited saprophytic fungi, while inhibiting fungal pathogens. Due to plant legacy effects on the soil microbial communities, different microbial successions occurred in the two previously planted soils when subjected to plant litter. By contrast, plant legacy effects on soil basal respiration were not plant-specific, with basal respiration increasing similarly in both cases and moreover did not translate to changes in litter carbon mineralization in the short-term of 49 days. Our results suggest that the soil nutrient dynamics rather than changes in soil microbial community composition drive the organic carbon mineralization of added litter. The present study brings new insights in how the relationships between plants, microorganisms and soil nutrient dynamics affect litter carbon cycling.

植物通过其根系结构、根系沉积物和死亡植物材料返回土壤来塑造土壤微生物群落。这些相互作用可以对土壤有机碳动态产生强烈影响。然而，尚不清楚植物物种对土壤微生物群落的影响是否会通过植物遗产效应影响有机碳矿化。因此，我们研究了短期植物生长阶段如何以及在多大程度上影响了总的和活跃的土壤微生物，并通过可能的植物遗产，以及土壤有机碳的矿化，这是一个中心生态系统功能。使用受控盆栽实验，我们首先证明了两种系统发育不同的植物，拟南芥和普通小麦，当从同一土壤群落招募时，土壤微生物群落的形状不同。尽管这两种植物都在其根部附近招募了促进植物生长的细菌，但拟南芥的作用比普通小麦强并且还招募了腐生真菌，同时抑制了真菌病原体。由于植物遗留对土壤微生物群落的影响，当受到植物凋落物的影响时，两种先前种植的土壤中发生了不同的微生物演替。相比之下，植物遗留对土壤基础呼吸的影响不是植物特异性的，两种情况下的基础呼吸增加相似，而且在 49 天的短期内没有转化为凋落物碳矿化的变化。我们的结果表明，土壤养分动态而不是土壤微生物群落组成的变化驱动了添加凋落物的有机碳矿化。本研究为植物、微生物和土壤养分动态之间的关系如何影响凋落物碳循环带来了新的见解。